I brewed the Great Lakes Brewing Eliot Ness clone again today. What I wound up with was 12.25 gallons of piping hot wort with an SG of 1.058. Once it cools, I should have about 11.75 gallons. Can I count on an increase in SG (to about 1.061) with this decrease in volume?

Ken - You could end up higher, depending upon the way you computed the 1.058 gravity.

Did you adjust it for temperature? 1.058 (piping hot) is greater than 1.058 at 60 d. adjusted for temperature. Since you are an "old pro" You probably did not make that mistake - So -consider the following:

Reducing 12.25 Volume to 11.75 of wort at 1.058 should get you close to 1.061.

Actually I get 1.0603673 - unless my math is F--- uped!Love This Hobby!

Actually, I used an eyedropper, which I figure cools the sample quickly with very little evaporation, and checked it with a refractometer.

I know if I boiled off that half gallon, I would get about a 3 point gravity increase. But I'm not boiling it off. I'll lose that half gallon due to wort contraction upon cooling, using the 4% rule of thumb.

Methinks you doth worry too much. But then again, I am a seat of the pants type of brewer and have yet to measure things like strike water to grist ratio and my actual yield.

I am a 10 gallon all-grain brewer and have consistently had 70-75% efficiency* (as measured by Promash after knockout). When I mash in, I do it by feel. When I fly-sparge, I do it until the brew kettle "looks about full." (full enough for a vigorous boil).

*Recently I tried batch sparging for the first time and came out a little lighter than expected.Give a man a beer and he'll waste an hour. Teach a man to brew and he'll waste a lifetime.

i just pitched the yeast for this beer, and took a sample. It reads 14.9 Brix. It WAS 14.3 Brix when hot. This corresponds to 1.058 hot, and 1.061 cold. Three degrees, like we were talking. No time to take a volume measurement. I'll do that tonight. Interesting.

Ken, if you take a couple of drops of the hot wort and check it with a refractometer, the sample cools to the temperature of the refractometer in a couple of nanoseconds. So you are measuring the SG of the cold wort. When the hot wort cools to room temperature it will still have the same SG you measured. In your cast is was a couple of points off. I suspect it was measurement error .

Richard, I used an eyedropper, and I agree the sample I measured was indeed cooled. Thanks for making me feel dumb.

This unit does have ATC though. I'm puzzled by the two different measurements. 14.3 and 14.9 are pretty far apart in that viewfinder. If anything, you'd think the hot measurement would more likely be high due to possible evaporation during the transfer of the drop of wort.

Also, I did the volume measurement, and it dropped only 1/4 gallon, not the half gallon which would be 4%.